Effective methods for the recovery and/or separation of particular ions such as certain transition metal ions, of which MN.sup.2+, Ni.sup.2+, Cu.sup.2+ and Cd.sup.2+ are illustrative, from other ions such as H.sup.+, Na.sup.+, K.sup.+, Mg.sup.2+, Ca.sup.2+, and Fe.sup.3+, and, the recovery and/or separation of metal ions, such as the transition metal ions, from other metal ions in water supplies, waste solutions, e.g., from emulsions on photographic and X-ray film, particularly those which contain large amounts of H.sup.+, represent a real need in modern technology. These ions are often present at low concentrations in solutions containing other ions at much greater concentrations. Hence, there is a real need for a process to selectively concentrate and recover these ions.
It is known that pyridine containing hydrocarbon ligands present as solutes in a solvent such as water, are characterized by their ability to selectivity form strong bonds with many transition metal cations such as Mn.sup.2+, Ni.sup.2+, Cu.sup.2+, Cd.sup.2+, and others or groups of these ions present as solutes in the same solvent, even in the presence of relatively large amounts of H.sup.+, and other common cations such as Na.sup.+, K.sup.+, Mg.sup.2+, Ca.sup.2+, and Fe.sup.3+, as described by Smith et al., CRITICAL STABILITY CONSTANTS, Volumes 2, 5, 6, Plenum Press, New York, 1975, 1982, 1989. However, researchers have not previously been able to incorporate pyridine-containing hydrocarbon ligands into separation systems where the behavior of the pyridine-containing ligands in the separation systems, in comparison to that of the pyridine-containing ligand as a solute, is unchanged and the pyridine-containing ligand will remain in the separation system covalently bonded to an inorganic solid support such as silica gel. Articles such as those entitled SILANE COMPOUNDS FOR SILYLATING SURFACES by E. P. Plueddemann, in "Silanes, Surfaces and Interfaces Symposium, Snowmass, 1985," Ed. by D. E. Leyden, Gordon and Breach, Publishers, 1986, pp. 1-25 and SILANE COUPLING AGENTS by E. P. Plueddemann, Plenum Press, 1982, pp. 1-235 list many different types of organic materials which have been attached to silane compounds and discusses some of their properties. The preparation and uses of pyridine-containing hydrocarbons attached to silane or silica have not been disclosed in the above mentioned articles or in any existing patents. Representative of patents describing the attachment of pyridine-containing hydrocarbons to hydrophobic polymers are Hancock et al., UK Patent 2,071,120, issued Sept. 16 1981; Jones et al., U.S. Pat. No. 3,998,924, issued Dec. 21, 1976; Grinstead, U.S. Pat. No. 4,451,375, issued May 29, 1984; Grinstead et al., U.S. Pat. 4,031,038, issued June 21, 1977; and Belgian Patent 887,872, published July 1, 1981. However, the materials described in these patents have ion exchange properties which alter selectivity as well as reduced and altered pyridine complexing properties due to the hydrophobic support. Thus, the unique complexing properties of certain pyridine containing hydrocarbons and the ability to attach these pyridine-containing complexing agents to inorganic solid supports such as sand or silica gel without reducing their ability to complex certain metal ions has heretofore been unknown but has been found to be of utmost importance in the industrial use of the pyridine-containing hydrocarbon ligands. That is the subject matter of the present invention.